Unravelling the (sub)cellular mechanisms of low frequency electromagnetic stimulation as ischemic stroke therapy

Event Abstract Back to Event Unravelling the (sub)cellular mechanisms of low frequency electromagnetic stimulation as ischemic stroke therapy Hannelore Kemps1*, Yörg Dillen1, Lena Perez Font2, Bert Brône1, Robin Lemmens3 and Annelies Bronckaers1 1 Biomedical Research Institute, Hasselt University, Belgium 2 Centro Nacional de Electromagnetismo Aplicado, Universidad de Oriente Cuba, Cuba 3 VIB & KU Leuven Center for Brain & Disease Research, Laboratory of Neurobiology, Belgium Neuroprotection for the treatment of acute ischemic stroke has been unsuccessful in clinical practice. We explored low frequency electromagnetic stimulation (LF-EMS) as an emerging safe and non-invasive neuroprotective therapy for ischemic stroke. Previous data indicated LF-EMS to ameliorate neurological outcome in rats subjected to global cerebral ischemic stroke, which was likely mediated by nitric oxide (NO). However, the mechanism by which NO production is induced remains unknown. Here we studied the effect of LF-EMS on NO production via activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (EC) and the therapeutic response in an experimental focal stroke mice model. eNOS activation is regulated by phosphorylation on multiple amino acid residues. Phosphorylation of eNOS (peNOS) at Thr495 negatively regulates eNOS function, while phosphorylation at Ser1177 enhances eNOS activity. To evaluate eNOS phosphorylation, EC were stimulated with LF-EMS (13.5 mT, 60 Hz) for 20 min or left unstimulated and were subjected to Western Blot analysis. LF-EMS significantly increased peNOS at Ser1177 (p=0.049, n=7) and decreased Thr495 phosphorylation (p=0.027, n=7) in EC, suggesting enhanced eNOS activation. To identify possible upstream targets responsible for eNOS phosphorylation, a human phospho-kinase array was performed. Based on this array, phosphorylation of Akt at Ser473 was investigated by Western Blot. Phosphorylated Akt, which is an important inducer of peNOS at Ser1177, was not significantly enhanced in EC in response to LF-EMS (p=0.080, n=9). Moreover, the effect of LF-EMS on infarct volume was assessed in the distal middle cerebral artery occlusion (dMCAO) model. dMCAO operated C57BL/6J mice were subjected to sham treatment or LF-EMS (13.5 mT, 60 Hz) for 20 min during 4 days. After 7 days, animals were sacrificed and brain slices were stained with TTC. We observed that LF-EMS treated dMCAO mice show a trend towards a reduction of 25% in infarct size compared to sham treated dMCAO mice (p=0.078, n=9). Our findings indicate that LF-EMS enhances eNOS activation by modulating its phosphorylation status at Ser1177 and Thr495. However, the phosphorylation of the possible upstream kinase Akt is not increased in response to LF-EMS. Other interesting targets identified from the phospho-kinase array will be investigated in future experiments. Data obtained from the dMCAO mouse model suggest that LF-EMS results in reduced infarct volumes compared to sham treated mice. In conclusion, this study provide more insight into the subcellular mechanisms of LF-EMS, which aid into its clinical translation as an effective therapy for ischemic stroke. Layman’s Summary: Current therapies for stroke are unable to sufficiently improve functional outcome in patients. We explore magnetic field (MF) stimulation as an emerging safe and non-invasive therapy for the treatment of stroke. Initial experiments performed in a stroke mice model show that MF-treated animals have a reduced infarct size of 25% compared to control animals. Additionally, we investigated which proteins are changed after MF treatment in endothelial cells, known as cells aligning the blood vessels. By elucidating these mechanisms, we aim to gain more insight into the therapeutic potential of MF stimulation as stroke therapy. Acknowledgements This study was performed at the Biomedical Research Institute (BIOMED) of UHasselt and was supported by the Special Research Fund (BOF) of Hasselt University (18NI06BOF). Keywords: ischemic stroke, Low frequency electromagnetic field, Nitric Oxide, endothelial nitric oxide synthase, dMCAO, Endothelial Cells Conference: Belgian Brain Congress 2018 — Belgian Brain Council, LIEGE, Belgium, 19 Oct - 19 Oct, 2018. Presentation Type: e-posters Topic: NOVEL STRATEGIES FOR NEUROLOGICAL AND MENTAL DISORDERS: SCIENTIFIC BASIS AND VALUE FOR PATIENT-CENTERED CARE Citation: Kemps H, Dillen Y, Perez Font L, Brône B, Lemmens R and Bronckaers A (2019). Unravelling the (sub)cellular mechanisms of low frequency electromagnetic stimulation as ischemic stroke therapy. Front. Neurosci. Conference Abstract: Belgian Brain Congress 2018 — Belgian Brain Council. doi: 10.3389/conf.fnins.2018.95.00072 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Aug 2018; Published Online: 17 Jan 2019. * Correspondence: Ms. Hannelore Kemps, Biomedical Research Institute, Hasselt University, Hasselt, Limburg, BE3500, Belgium, hannelore.kemps@uhasselt.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Hannelore Kemps Yörg Dillen Lena Perez Font Bert Brône Robin Lemmens Annelies Bronckaers Google Hannelore Kemps Yörg Dillen Lena Perez Font Bert Brône Robin Lemmens Annelies Bronckaers Google Scholar Hannelore Kemps Yörg Dillen Lena Perez Font Bert Brône Robin Lemmens Annelies Bronckaers PubMed Hannelore Kemps Yörg Dillen Lena Perez Font Bert Brône Robin Lemmens Annelies Bronckaers Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.